The present invention relates to an agricultural vehicle with a treatment device which is adjustable relative to the vehicle in its position and orientation, wherein the agricultural vehicle is provided with a GPS satellite navigation receiving unit.
Agricultural vehicles such as harvesters, tractors, etc as a rule are provided with a treatment device which is movable and/or adjustable to achieve a spacial position and orientation. Such treatment devices are for example a cutting bar of a harvester, a plough of a tractor, and a device for applying fertilizers or plant protective agents. The position and orientation of the treatment device relative to the vehicle are influenced by manual control by a vehicle driver or by an automatic regulation with sensors for determination of the position and orientation. The control of the position and orientation of the treatment device can be both active so as to operate by controlling of adjusting drives (for example a front loader on a tractor), and also passive by controlling of the vehicle (for example a vehicle trailer).
Other agricultural vehicles are known, in which, in addition to the position and orientation of the treatment device relative to the vehicle, also the position and orientation of the treatment device relative to the ground surface is changeable. For example in a combined harvester, a device and a method are known in accordance with which the cutting height or in other words the height of the cutter bar over the ground surface can be adjusted and regulated. With the adjustment and regulation of the position and orientation of the treatment vehicle, frequently nominal and limiting values for the parameter which describe the position and orientation are provided. Thus, nominal values for the cutting height of a combined harvester in dependence on the harvested product are known. A lower limiting value for the cutting height is determined so as to prevent damages to the cutter bar. An upper limiting value is determined by the growth height of the harvested product.
The position and orientation of the treatment device relative to the vehicle and relative to the ground are dependent on one another. The dependency is determined by the properties of the ground and therefore generally is known only insufficiently. For the operation of the agricultural vehicle is the position and orientation of the treatment device relative to the ground is however important. Methods are known, in accordance with which the position and orientation of the treatment device relative to the ground are measured, and the position and orientation relative to the vehicle is regulated by adjustments. This is provided for the operation of a combine harvester, for example by an AUTO-CONTOUR method of the applicant. In many cases, however, the vehicle driver compensates the changed ground property by a manual control.
Furthermore, from the German patent document DE 44 31 824 C1 a method is known, which connects the operational data of a combine harvester with the corresponding space coordinate determined in a historic data cadastre and provides from it nominal or limiting operational values for a new treatment. The space coordinates are determined in the prior art by means of a satellite navigation system on the vehicle.
Furthermore, the German patent document DE 195 44 112.5 discloses a method for generation of three-dimensional digital terrain models with a vehicle having a satellite navigation system. For the generation of digital terrain models and the generation of data cadastres in the known method the position of a point on the vehicle is considered to be as the basis. For the operation of the vehicle however the position and the orientation of the treatment device is decisive. The accuracy of the produced terrain model is therefore not better than the dimensions of the vehicle permit. This can lead, especially for large machines with broadly arranged treatment devices, to inaccuracies in the terrain model or in data cadastre. The high accuracy of the currently available satellite navigation systems is not completely used in this method. When it is necessary in addition to use the operation data cadaster for regulation of the position and orientation of the treatment device, then the uncertainties in the position of the treatment device make necessary the control and eventually the engagement of the vehicle driver. Since the above mentioned uncertainties first of all occur on uneven terrain, in which the concentration of the vehicle driver must be increased anyway, this can lead to the fact that the efficiency of the agricultural vehicle is not fully utilized or operational disturbances are caused.